Thermal insulator



J June-2, 1936- J. CAMPBELL ET AL 2,042,585

V THERMAL INSULATOR Filed Feb. 24, 1933 INVENTORS JOHN CAMPBELL ROBERT a pu/xv ATTORNE Patented June 2, 1936 UNITED STATES PATENT OFFICE" 2,042,588 I F r THEBMALINSULATOB New York, N. Y.,

and Robert G. Quinn, Glens. Falls,

to International Paper Ooma corporation of New Application February 24, 1933, Serial No. 658,371

scum. (01-154-45) This invention relates to an insulation D:

struction and particularly to that class of insul5 forced or otherwise strengthened, and are consequently not only costly to manufacture but often do not possess the necessary and desired insulating characteristics. The primary feature of this invention, therefore, is to provide a new 0 and improved insulation unit which effectively meets all of the requirements of a satisfactory insulator and yet, which at the same time, is relatively cheap to manufacture and assemble. I Another feature of this invention is to provide a new and improved thermal insulation unit made up of a plurality of sheets of paper which have been previously impregnated, coated, contained or saturated with a waterproofing material and then corrugated. [Sheets thus formed may be assembled into a pack and then sewed or stapled together, thus avoiding the use of adhesive to hold the sheets together.

A further feature of this invention is to provide an improved thermal insulation unit comprising a plurality of sheets of waterproofed corrugated paper united together in such a manner that the number of contacts between sheets through a cross section of the unit and the area of such contact points are reduced to a minilo mum, thereby reducing the rate of flow of heat through the unit.

A still further feature of this invention is to provide an insulation construction made up ofa plurality of corrugated sheets of paper which 46 have been previously treated with a waterproofing and/or stiffening material of such character that the air cells formed by the corrugations may be designed within close limits to obtain a minimum heat transferv by convection. In other i 50 words, the optimum still air condition may be obtained. Moreover, the material which the sheets contain, through impregnatio coating or through addition in manufacture previous to formation into sheets, renders the sheets resistant to capillary and hygroscopic action. Sheets so treated do not have their strength and insulating valu'e appreciably decreased whenlexposed to moisture.

With these and further features in view as will in part be hereinafter stated and in part become the invention comprises certain more apparent, novel constructions and arrangement of parts as subsequently specified and claimed. In the accompanying drawing,-

Fig. -1 is a perspective view of the new and improved insulation unit;

broken away struction.

Fig. 2 is an end unit looking in the of Fig. 1.

elevation of a portion of the direction of the arrows {-2 15 Fig. 3 is a similar view but showing a modified form of insulation unit.

7 Referring now more particularly to the drawing in which like there is shown an insulation unit numerals indicate like parts In comprising a plurality of superimposed corrugated sheets ll. Each of these sheets H consists of a length of paper which has been saturated or impregnated with asphalt up to the extent of 50% of its weight. The paper proved insulating-un't is a wellten -flbre,

rating afterward with steam-blown asphalt or other hard waterproofing of forming a rigid the characteristic be appreciated that lower the weight of sheet used in constructing the im- 25 preferably made by using silicate of soda, and by satusubstance which has film. It will the stiffer the sheet is, the

necessary, and consequently the better the resultant insulation, since the solid fraction of the product is less. I have found that the minimum the sheet must be corrugated,

requirements are that still enough so that, when the corrugations will retain their shape and not flatten out. Thedmpregnation orcoating a ent must to avoid excessive be sufflciently thermo-plastic brittleness during corrugating.

The use of too brittle an impregnating agent might readily cause the sheet to break orto peel oft in pa i through if the higher melting bitumens are used only be impregnated to the extent of its weight. If desired, however, saturated or impregnated with Montan wax, sulphur,

gums. Paper thus treated is Hence, the paper need of 25% or less the paper may be thetic resins, or

the corrug'ating rolls.

coumar resin or other syncomparatively rigid and can be corrugated with less corrugations per tofore been considered possible.

which has not been treated in gating of paper this manner it has running foot than has here- In the corrubeen found necessary to glue parts thereof being to show certain details of' conor cement afacing sheet to the corrugated paper to enable such paper satisfactorily to serve the purpose for which it was intended. The use of asphalt impregnated paper does away with the handling andequipment involved in pasting the facing sheet on the corrugated paper.

As will be noted the flutes II of alternate sheets of asphalt impregnated paper are disposed at right angles to the flutes l3 of adjacent sheets. The unit is held together by stitching ll. This construction not only affords considerable stiifness in the finished unit but also serves to reduce the flow of heat therethrough. In prior practice the paper usually employed would not possess suflicient mechanical strength unless the paper was so corrugated that the flutes thereof were of considerable height and the numberof flutes in each running foot ofpaper was accordingly great. When a number of such sheets, having cemented or glued thereto facing sheets, were built into a unit the number of positive contact points through a cross section of the unit and the area of such contact points were large. The insulating value of the completed unit was low and the cost of manufacture high.

' By the use of corrugated asphalt impregnated or saturated sheets the above described difllculties were avoided. The sheets thus formed can be stitched together avoiding the formation of positive contacts between sheets, the number of places of contacts can be reduced as can also the area of such contacts. "Such construction consequently reduces the flow of heat through the unit to a minimum and is a distinct advance in the manufacture of suitable insulation units. Since paper impregnated or saturated with asphalt is moisture resistant the unit maybe subjected to moisture containing fluids without the danger of decay and without an appreciable decrease in the insulating value thereof.

In many cases it is necessary that the thermal insulating unit be so treated as to withstand the eflect of fungi and insects. Thermal insulating units possessing this characteristic may be reads ily obtained by treating the paper with copper salts, arsenic compounds, chlorinated .diphenyls or naphthalenes.

In Fig.8 there is shown a modified form of insulation unit III in which the flutes l5 are themselves provided with flutes l6. Such construction serves to still further decrease the area of the contact points between the sheets making up right angles to the frictional rolls of a conventional stitcher with enough space between them to permit the insertion of sheets of similarly treated paper equal in length to the width of the several webs. The corrugations of the paper 5 moving in the continuous webs are parallel with the friction rolls of the stitcher. The corrugations of the sheets run at right angles to the friction rolls of the stitcher. When these latter sheets have been moved into superimposed rela- 10 tion with the webs of material they are cut, and the insulation thus formed is sewed together without compressing the layers forming the said unit. It may be sometimes desirable to use sheets varying in width. After stitching the assembled 15 web is slit into thedesired dimensions.

From the above description it will be appreciated that the invention comprises a new and novel thermal insulation unit which satisfactorily meets all requirements of an insulator designed 20 primarily for use in refrigeratorfand building construction. It will also be readily appreciated by those skilled in the art to which this invention appertains that several modifications may be be made in the construction and arrangement of 2 partswithout departing from the spirit of the invention or the scope of the appended claims.

We claim: 1

1. A thermal insulator comprising a plurality of superposed sheets of waterproofed corrugated 30 paper, each flute of which is itself corrugated throughout its length whereby' to reduce the effective area of contact between the corrugations of the sheets, and stitching connecting said sheets together.

2. a thermal insulator comprising a plurality of superposed sheets of waterproofed corrugated paper, the flutes of alternate sheets running at an angle to flutes of adjacent sheets, each flute of each sheet being in itself corrugated throughout its length, whereby to reduce the effective area of contact between the corrugations in the sheets, and stitchingconnecting said sheets together. I 1

3. A thermal insulator comprising a plurality of sheets of corrugated paper arranged in superimposed relation, each sheet being saturated up to 50% of its weight with asphalt capable of forming a rigid fllmwhereby the corrugations of each sheet will retain their shape, the flutes of adjacent sheets having substantially point contact with each other. and means connecting said sheets together. Y

- JOHN CAMPBELL.

ROBERT G; QUINN. 55 

